Publications by authors named "Valerie LeBlanc"

Infertility is constantly increasing in Canada, where 16% of Canadian couples are experiencing difficulty conceiving. It is thought that infertility can emanate from the dysregulated communication between the embryo and the maternal endometrium. In order to allow for this window of implantation to be open at the right moment, endometrial stromal cells proliferate and differentiate by a mechanism called decidualization.

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The search for new specific chemotherapeutic drugs designed to minimize the toxic side effects resulting from chemotherapy is still a subject of intense research. The objective of the current study was to design a non-steroidal-platinum(II) derivative that would target the estrogen receptor alpha (ERα) without triggering estrogenic cell proliferation. For this purpose, the amino acid L-tyrosine was modified and attached to a cisplatin analog.

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Prostate cancer (PC) is a major health issue in the world. Treatments of localized PC are quite efficient and usually involve surgery, radiotherapy and/or hormonal therapy. Metastatic PC is however rarely curable to this day.

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The synthesis of 7α-testosterone-chlorambucil hybrid is reported. This compound is made from testosterone in a 6 step reaction sequence and with 23% overall yield. An alternative convergent reaction sequence yielded the same hybrid through a Grubbs metathesis reaction between chlorambucil allyl ester and 7α-allyltestosterone with 35% overall yield.

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The occurrence of apoptosis and cell survival in the receptive uterus is intimately involved in the embryo implantation process in order to facilitate embryo attachment to the maternal endometrium. The initial stimulus leading to successful implantation might be triggered by the conceptus itself. By the end of rat embryo implantation, decidualization begins, followed by the regression of the decidua basalis on Day 14.

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Objective: In tumors, upstream regulation of Akt is affected by oncogenic events which lead to its constitutive activation and promote cell survival. Since studies have demonstrated that the three Akt isoforms exhibit different physiological functions, Akt isoforms may contribute differently in chemoresistance. The objective of the study was to determine the role of each Akt isoforms in chemoresistance.

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Doxorubicin (DOX) is an important medicine for the treatment of breast cancer, which is the most frequently diagnosed and the most lethal cancer in women worldwide. However, the clinical use of DOX is impeded by serious toxic effects such as cardiomyopathy and congestive heart failure. Covalently linking DOX to estrogen to selectively deliver the drug to estrogen receptor-positive (ER(+)) cancer tissues is one of the strategies under investigation for improving the efficacy and decreasing the cardiac toxicity of DOX.

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Objective: To compare body temperature of the late preterm infant after 24 hours of life at three time points before and after immersion tub bathing or sponge bathing. We hypothesized that late preterm infants achieve significantly improved thermoregulation when bathed by immersion tub bath compared to traditional sponge bathing.

Design: This study was a randomized controlled trial.

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L-para-Tyrosine was linked to ortho-hydroxyaniline, meta-hydroxyaniline and para-hydroxyaniline giving three distinct tyrosinamide molecules. The new extended amino acid derivatives were constructed to imitate, in part, the estradiol (E(2), the natural female sex hormone) nucleus. The resulting tyrosinamides were then linked to chlorambucil either directly, or via a 5 and 10 carbon atoms spacer chain.

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In the course of efforts to develop 17β-estradiol-linked to anticancer agents targeting estrogen-dependent tissue, we identified three estradiol-linked platinum(II) complex analogs to cisplatin (E-CDDP) derivatives namely: VP-128 (1), CD-38 (2) and JMP-39 (3) that exhibit potent in vitro and in vivo (for derivative VP-128) activity along with interaction with the estrogen receptor α (ERα). In this study, we prepared and biologically evaluated two novel classes of estradiol-linked platinum(II) complex analogs to carboplatin (E-CarboP, 1a-3a) and oxaliplatin (E-OxaP, 1b-3b). E-CarboP and E-OxaP were designed and based on the estradiol-linker scaffold of E-CDDP derivatives previously identified.

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Amino acids were transformed and coupled to chlorambucil, a well-known chemotherapeutic agent, in an attempt to create new anticancer drugs with selectivity for breast cancer cells. Among the amino acids available, tyrosine was selected to act as an estrogenic ligand. It is hypothesized that tyrosine, which shows some structural similitude with estradiol, could possibly mimic the natural hormone and, subsequently, bind to the estrogen receptor.

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Traditionally, oxytocin (OT) is well known to play a crucial role in the regulation of cyclic changes in the uterus, implantation of the embryo, and parturition. Recently, an additional role for OT has been identified in several types of cancer cells in which OT acts as a growth regulator. In endometrial cancer cells, OT is known to efficiently inhibit cellular proliferation.

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Human carcinomas often show resistance to cisplatin and Bcl-2 is associated with resistance to cisplatin. However, Bcl-2 regulation on cisplatin treatment in human cancers is unknown. Here, we show a novel mechanism by which cisplatin treatment promotes resistance by increasing the expression of Bcl-2 mRNA.

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Resveratrol (trans-3,4N-trihydroxystilbene), a phytoalexin present in grapes and red wine is emerging as a natural compound with anticancer properties. However, the physiological and molecular effects of resveratrol on normal uterine cells are poorly understood. In the present study we evaluated the effects of resveratrol on normal uterine cells and the mechanisms involved in vivo.

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A series of D- and L-tyrosine-chlorambucil analogs was synthesized as anticancer drugs for chemotherapy of breast cancer. The novel compounds were synthesized in good yields through efficient modifications of D- and L-tyrosine. The newly synthesized compounds were evaluated for their anticancer efficacy in different hormone-dependent and hormone-independent (ER+ and ER-) breast cancer cell lines.

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The synthesis of a series of 17β-estradiol-platinum(II) hybrid molecules is reported. The hybrids are made of a PEG linking chain of various length and a 2-(2'-aminoethyl)pyridine ligand. They are prepared from estrone in only 5 chemical steps with an overall yield of 22%.

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Background: Cyclooxygenases (COXs) are the rate limiting enzymes in the process of prostaglandins (PGs) synthesis, which are critical regulators of a number of reproductive processes, including ovulation, implantation, decidualization and parturition. The aim of the present study was to investigate the expression and regulation of COX-1 and COX-2 and levels of prostaglandins during rat pregnancy, in a model of pseudopregnancy and estrous cycle.

Methods: Uteri were collected from the cyclic rats on each day of estrous cycle, after every two days for pregnant (days 2 to 22) and pseudopregnant rats (days 1 to 9).

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Background: X-linked inhibitor of apoptosis protein (XIAP) is often overexpressed in cancer cells, where it plays a key role in survival and also promotes invasiveness. To date however, the extracellular signals and intracellular pathways regulating its expression and activity remain incompletely understood. We have previously showed that exposure to each of the three TGF-beta (transforming growth factor beta) isoforms upregulates XIAP protein content in endometrial carcinoma cells in vitro.

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The synthesis of two separable isomeric testosterone dimers is reported. The dimers are made from testosterone in a 5 step sequence and with 36% overall yield. The key dimerization step was performed using Hoveyda-Grubb's metathesis catalysts on 7alpha-allyltestosterone with 75% yield.

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A series of estradiol-chlorambucil hybrids was synthesized as anticancer drugs for site-directed chemotherapy of breast cancer. The novel compounds were synthesized in good yields through efficient modifications of estrone at position 16alpha of the steroid nucleus. The newly synthesized compounds were evaluated for their anticancer efficacy in different hormone-dependent and hormone-independent breast cancer cell lines.

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We have previously reported the synthesis of VP-128, a new 17beta-oestradiol (E(2))-linked platinum(II) hybrid with high affinity for oestrogen receptor alpha (ERalpha). In the present study, we have investigated the anti-tumour activity of VP-128 towards breast cancer cells in vitro and in vivo. We used human ERalpha-positive (MCF-7) and -negative (MDA-MB-468) cells as a model for treatment with increasing doses of VP-128, cisplatin or E(2) in vitro and for xenograft experiments in nude mice in vivo.

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Background: During the estrous cycle, the rat uterine endometrium undergoes many changes such as cell proliferation and apoptosis. If implantation occurs, stromal cells differentiate into decidual cells and near the end of pregnancy, a second wave of apoptosis occurs. This process called decidual regression, is tightly regulated as is it crucial for successful pregnancy.

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Background/rationale: Various interventions are available to manage verbal agitation (VA), but our understanding regarding their acceptability is limited. The purpose of this study is to compare the acceptability of 3 interventions from the point of view of elderly individuals: direct interaction (DI), differential reinforcement of incompatible behaviors (DRI), and risperidone (RIS).

Methods: Participants (N = 69) evaluated the acceptability of each treatment according to the description of a fictional person who demonstrated aggressive or nonaggressive VA.

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Apoptotic cell death plays a normal role in various physiological processes, and deregulated apoptosis is a hallmark of several diseases, including cancer. Cell fate is dictated by the balance between pro- and antiapoptotic factors. Akt is one of these antiapoptotic factors, which must be activated through phosphorylation.

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We have recently reported the synthesis of a platinum(II) complex, made of estradiol, the female sex hormone, and a cisplatin analog, an anticancer drug, linked together by an eleven carbon atoms chain. The novel estradiol-Pt(II) hybrid molecule was synthesized in nine chemical steps with 10% overall yield. This new compound has been tested in vitro on estrogen-dependent (MCF-7) and -independent (MDA-MD-231) (ER(+) and ER(-)) cell lines.

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